We’ve been led to believe that all stress is bad—but that isn’t the case. In fact, getting enough stress can be beneficial to your health. According to the October ’10 Reader’s Digest, scientists at Ohio State University put a group of mice in either a fairly stress-free environment with a few cage mates and toys or a more challenging one with lots of cage mates and a bunch of toys. Then they injected all the subjects with cancer cells. Result: “Tumors were as much as 77 percent smaller in the mice with lots going on, and one in six of this group avoided cancer entirely.” The study shows that short-term manageable challenges, even if somewhat uncomfortable, can boost the immune system.